Heat actuated closure for containers



E. JOHNSON 2,881,944

April 14, 1959 HEAT ACTUATED CLOSURE FOR CONTAINERS 4 Sheets-Sheet 1Filed Jan. 29, 1957 April 14, 1959 E. JOHNSON 2,

HEAT ACTUATED CLOSURE FOR CONTAINERS Filed Jan. 29, 1957 v v 4Sheets-Sheet 2 April 14, 1959 E. L. JOHNSON HEAT ACTUATED CLOSURE FORCONTAINERS 4 Sheets-Sheet 3 Filed Jan. 29, 1957 3 3 v 3 Na wN vN MN on 7April 14, 1959 E; L. JOHNSON 2,881,944

HEAT ACTUATED CLOSURE FOR CONTAINERS Filed Jan. 29, 1957 4 Sheets-Sheet4 INVENTOR. [CA 57 A. J #17504 a,as1,944

' HEAT ACTUATED LOSURE FOR CONTAINERS :Ernest L. Johnson, Sacramento,Calih, assignor to the United S ates of America as represented by theSecretary of the Force Application January 29, 1957,:Serial No. 637,050v1 Claim. c1. 220-88) (Granted :under Title 35, 13. S. Code (1952), see.266') The invention described herein may be manufactured and used by orfor the United States Government for governmental purposes withoutpayment to me of any royalty thereon.

This invention relates to a storage bin, and more particularly, to aheat actuated closure device for a storage a bin adfipted'to holdinflammable or explosive material.

Thermal or heat actuated closure devices for storage bins are wellknown, and have functioned well for safeguarding certain kinds ofinflammable material. They have been less satisfactory where the storagebin was used to store sensitive high explosive materials, because theydid not exercise any control over the rate at which the bin was sealedwhen the thermal device was actuated. If the container closure was aheavy cover, the shock produced by the cover slamming shut over thestorage bin could cause an explosion in the material inside thecontainer.

Accordingly, the principal object of this device is to provide a heatactuated closure device for a storage bin provided with means forcontrolling the force of engagement between the storage bin and itscover.

An additional object of this invention is to provide a storage bin forthe storage of combustible or explosive materials having acounterweighted heat actuated cover.

Still another object of this invention is to provide a heat actuatedclosure device for a storage bin provided with means for controlling thespeed at which the storage bin is closed.

Yet another object of this invention is to provide a storage bin for thestorage of explosive and combustible materials which is simple tomanufacture, economical and safe.

These and further objects of this invention will become more apparentwhen read in the light of the accompanying specification and drawingswherein:

Figure 1 is a front perspective view of the storage bin with the coverclosed.

Figure 2 is a front perspective view of the storage bin with the coveropen.

Figure 3 is a rear perspective view of the storage bin with the coverclosed.

Figure 4 is a side view of the storage bin with the cover closed.

Referring now to Figure 1 of the drawing, a storage bin indicatedgenerally at comprises a container 12 and a cover 14. The cover ispivotally secured to the container by hinges or pivots 16. A back stop18 for cover 14 is rigidly mounted on the container 12. As best seen .inFigures 2 and 4 with the cover 14 opened to its widest extent so that itengages back stop 18, the center of gravity of the cover is such that ifleft to itself, it would fall back into its closed container sealingposition. To prevent this from happening, counterweights 20 and 22, seeFigure 3, are connected to the cover. These counterweights apply forcesto the cover which oppose the biasing force exerted by gravity. A pairof guide tubes 24 and 26 are rigidly secured to the rear surface of thecontainer,

2,881,944 Patented Apr. 14, 1959 and counterweights 20 and 22 ride inthese tubes. These guide tubes have several functions. They .control thedirection of the forces applied by the counterweights to the cover, andprotect and isolate the counterweights from each other .and from outsideforces.

A vertical upstanding :support 281s rigidly connected to the container12 and a shaft 30 is rotatably mounted in the upper end of this support.A pair of pulleys 32 and 34 .are rigidly secured to this shaft inspacedpar'auel 0 lationship. An additional pulley 42 and a fixed supportt or bracket 40 are connected to cover .14 for purposes to be describedbelow.

A cable or string .38 is connected at one end to counterweight 20. Itthen passes .over pulley 34, and vis fixedly secured at the opposite endto the cover 14 at bracket 40. Similarly, a cable or string 36.isconnectedat'one end to counterweight 22. It then passes over pulley 32and also over pulley 42 which is rotatably mounted "in cover 14, andmoves along the interior surface of cover 14 Where it terminates at thefusible link portion 44. This fusible link 44 is secured to thecontainer 12 by means of a bracket 46, see Figures 2 and 4. Themagnitudes of counterweights 20 and 22 are jointly suflicient to holdcover 14 in open position against back stop 18, but each individualcounterweight is not suificient to do so.

The operation of this closure is as follows: In the event the materialstored in the container becomes ignited or the temperature in the roomexceeds any predetermined amount, the fusible link 44 will meltdisconnecting counterweight 22 from cover 14. If this happens while thecontainer is in an open position, the force of gravity exerted on thecover will be greater than the opposing force exerted by the remainingcounterweight 20, causing the container cover 14 to close. The speed orrate of closure of the container cover can be regulated by controllingthe size of the remaining counterweight 20. In the event a container isstoring some high explosive material such as nitroglycerine, the speedat which the cover closes can be made as slow as desired to reduce theforce of engagement between the cover 14 and the container 12.

These counterweights also have an added utility. When the container islarge and the cover is heavy, they provide a means for easily openingthe container. It is apparent, for example, that weights 20 and 22 andthe height of support 28, can be so chosen that the cover is in a stateof complete equilibrium when the cover is in a position parallel to theground. Simple physical considerations show that such an equilibriumposition is unstable and that the slightest pressure on the coverexerted in an upward direction will cause the cover to open until itengages back stop 18, and the slightest pressure on the cover in adownward direction will cause the cover to slowly close. In addition tothe ease in opening the container provided by this arrangement, anadditional safety feature is apparent. When the container is large andthe cover is very heavy, this structure prevents the cover from slammingdown into closing position and possibly injuring the hands or arms ofpersons extracting material from the container at that moment.

It is apparent that many modifications can be made WlIhOllta departingfrom the spirit of the invention and accordingly, the above disclosureshould be considered as illustrative and not restrictive. The scope ofthe above invention should be determined by reference to the appendedclaims wherein:

I claim:

In a storage bin for the storage of combustible and explosive material,a container for housing combustible and explosive material, a coverhingedly mounted on said container normally biased towards the closedposition under action of gravity and having an opening incorporatedtherein adjacent the forward edge thereof, an upstanding support rigidlyattached to the rear surface of said container and extending upwardly toa substantial overhanging portion relative to the top of said container,a pair of spaced, parallel pulleys rotatably afiixed to and spaced fromsaid bracket and adjacent said opening, a

fusible link adaptable for separation at a predetermined temperaturemounted on the lower surface of said cover adjacent the rear edgethereof, a first cable aflixed at one end" to said bracket on the uppersurface of said coverand threaded over one of said spaced, parallelpulleys positioned adjacent the upper surface of said upstanding supportand terminating at its other end in one of said tubular guides, a secondcable attached at one end to said fusible link on the lower surface ofand adjacent the rear edge of said cover and having one section threadedthrough said opening incorporated adjacent the forward edge of saidcover, a second section threaded over the pulley mounted on the uppersurface of said cover adjacent said opening, and a third sectionextending from said last-named' pulley to the other of said spaced,parallel pulleys positioned adjacent the upper surface of saidupstanding support and terminating at its other end in the other of saidtubular guides, and a pair of counterweights within said tubularguides'and attached to the respective ends of said first and secondcables terminating in said tubular guides and cooperating with eachother to overbalance the normal biasing force of said cover and normallyretaining said cover in open, raised position, saidbiasing force beingin excess of the counterforce of the counterweight attached to saidsecond cable a predetermined minimum amount to gradually move saidcarrier to its closed position on destruction of said fusible link torelease the cooperating counterweight attached to said first cable.

References Cited the file of this patent UNITED STATES PATENTS 1,213,686Owens Ian. 23, 1917 1,683,571 Mueller Sept. 4, 1928 2,535,368 NorcrossDec. 29, 1950 2,679,949 Clinton June 1, 1954

